Day Four

3 files changed, 58 insertions, 0 deletions

diff --git a/2022/rust/day04/Cargo.lock b/2022/rust/day04/Cargo.lock
new file mode 100644
index 0000000..b8f9a18
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+++ b/2022/rust/day04/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "day04"
+version = "0.1.0"
diff --git a/2022/rust/day04/Cargo.toml b/2022/rust/day04/Cargo.toml
new file mode 100644
index 0000000..aa462dc
--- /dev/null
+++ b/2022/rust/day04/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "day04"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/2022/rust/day04/src/main.rs b/2022/rust/day04/src/main.rs
new file mode 100644
index 0000000..3f8b9cd
--- /dev/null
+++ b/2022/rust/day04/src/main.rs
@@ -0,0 +1,43 @@
+use std::env;
+use std::fs;
+use std::ops::RangeInclusive;
+
+fn main() {
+    let args = env::args().nth(1).expect("missing input");
+    let input = fs::read_to_string(args).unwrap();
+    let assignments = input.trim().split('\n').map(|x| {
+        let mut vec = x.split(['-',',']).map(|x| x.parse::<i32>().unwrap());
+        return [vec.next().unwrap(), vec.next().unwrap(),
+                vec.next().unwrap(), vec.next().unwrap()];
+    }).collect::<Vec<[i32; 4]>>();
+
+    println!("{}", assignments.iter()
+        .filter(|x| contains(x[0] ..= x[1], x[2] ..= x[3])).count());
+
+    println!("{}", assignments.iter()
+        .filter(|x| overlaps(x[0] ..= x[1], x[2] ..= x[3])).count());
+}
+
+fn contains(a: RangeInclusive::<i32>, b: RangeInclusive::<i32>) -> bool {
+    return b.contains(a.start()) && b.contains(a.end()) ||
+           a.contains(b.start()) && a.contains(b.end());
+}
+
+fn overlaps(a: RangeInclusive::<i32>, b: RangeInclusive::<i32>) -> bool {
+    return b.contains(a.start()) || b.contains(a.end()) ||
+           a.contains(b.start()) || a.contains(b.end());
+}
+
+/*
+fn main() {
+    let args = env::args().nth(1).expect("missing input");
+    let input = fs::read_to_string(args).unwrap();
+    let assignments = input.trim().split('\n')
+        .map(|x| {x.split(['-',',']).collect()})
+        .collect::<Vec<Vec<&str>>>();
+
+    println!("{:?}", assignments);
+
+}
+
+*/